According to the International Energy Agency, biorefinery is “the sustainable processing of biomass into a spectrum of marketable bio-based products (chemicals, materials) and bioenergy (fuels, power, heat)”. In this review, we survey how the biorefinery approach can be applied to highly porous and nanostructured materials, namely aerogels. Historically, aerogels were first developed using inorganic matter. Subsequently, synthetic polymers were also employed. At the beginning of the 21st century, new aerogels were created based on biomass. Which sources of biomass can be used to make aerogels and how? This review answers these questions, paying special attention to bio-aerogels’ environmental and biomedical applications. The article is a result of fruitful exchanges in the frame of the European project COST Action “CA 18125 AERoGELS: Advanced Engineering and Research of aeroGels for Environment and Life Sciences”.
Superparamagnetic iron oxide nanoparticles doped with zinc and modified with a cationic derivative of chitosan (SPION-Zn-CCh(+)) that exhibited enhanced activity in magnetic hyperthermia were synthesized and characterized structurally, magnetically, and biologically. The optimum zinc content and the polymer coating were found to be important to maximize the hyperthermic effect in the obtained nanoferrites, which effectively worked at concentrations as low as 0.55 mg Fe per mL. The average core diameter was found to be ca. 10 nm as revealed by SAXS and TEM measurements, while the formed small aggregates of the polymer coated nanoparticles reached a size of ca. 200 nm. The nanoferrite structure was further obtained using Mössbauer spectroscopy and XANES revealing the maximum Zn doping. The much higher (ca. 60%) intrinsic loss power determined for SPION-Zn-CCh(+) as compared to the native iron oxide nanoparticles, together with the long term (12 months) stability of their dispersion and biocompatibility, makes these nanoferrites very promising materials for magnetic hyperthermia therapy. The proposed synthetic method employing a cationic polysaccharide opens up also new opportunities for the formation of other metal ferrites with composition and structure previously unobtainable and potentially superior e.g. magnetic properties.
1 January 2019 in Colloids and Surfaces B: Biointerfaces
Cancer is among the leading causes of death worldwide, thus there is a constant demand for new solutions, which may increase the effectiveness of anti-cancer therapies. We have designed and successfully obtained a novel, bifunctional, hybrid system composed of colloidally stabilized superparamagnetic iron oxide nanoparticles (SPION) and curcumin containing water-soluble conjugate with potential application in anticancer hyperthermia and as nanocarriers of curcumin. The obtained nanoparticulate system was thoroughly studied in respect to the size, morphology, surface charge, magnetic properties as well as some biological functions. The results revealed that the obtained nanoparticles, ca. 50 nm in diameter, were the agglomerates of primary particles with the magnetic, iron oxide cores of ca. 13 nm, separated by a thin layer of the applied cationic derivative of chitosan. These agglomerates were further coated with a thin layer of the sodium alginate conjugate of curcumin and the presence of both polymers was confirmed using thermogravimetry. The system was also proven to be applicable in magnetic hyperthermia induced by the oscillating magnetic field. A high specific absorption rate (SAR) of 280 [W/g] was registered. The nanoparticles were shown to be effectively uptaken by model cells. They were found also to be nontoxic in the therapeutically relevant concentration in in vitro studies. The obtained results indicate the high application potential of the new hybrid system in combination of magnetic hyperthermia with delivery of curcumin active agent.
1 February 2017 in Colloids and Surfaces B: Biointerfaces